Pallets are widely used for the transportation of a wide variety of goods. An essential purpose of a pallet is to provide a support platform for the goods which allows a space below the goods for entry of the forks of a forklift. By far, the most popular pallet construction material is wood. A wooden pallet typically features a wooden platform and two or three wooden runners beneath the platform which provide for fork entry. Because of the cost of wood, it is usually economically necessary to reuse wooden pallets. Reuse often entails the expense of returning the empty pallets to the original shipment point.
It has long been the desire of the pallet industry to provide a pallet which is sufficiently inexpensive so that reuse is not necessary. In other words, the pallet would be discarded after its first use. There have been many attempts to design such a pallet, often using corrugated paperboard as the construction material. Examples of such pallets are formed in the patents to Fallert, U.S. Pat. No. 2,388,730; Fallert et al., U.S. Pat. No. 2,446,914; and Gifford, U.S. Pat. No. 3,464,371. There have also been attempts to design pallets which are fabricated from a combination of corrugated paperboard and wood stringers. This type of pallet is illustrated in the patents to Newsom, U.S. Pat. No. 2,702,682, and Hamilton, U.S. Pat. No. 2,904,297.
The present invention provides an improved patent of composite construction. The preferred materials are corrugated paperboard and wood. In its preferred form, the pallet has upper and lower panels of corrugated paperboard. Two or more runners are disposed between the upper and lower panels which are preferably fabricated from stacked corrugated paperboard. The corrugation of the runners are disposed vertically between the upper and lower panels, i.e., the edges of the corrugated paperboard mate with the upper and lower panels. The runners are notched to receive two or more wood stringers which extend transversely of the runners. The depth of the notches is substantially the same as the thickness of the stringers so that the upper surface of the wooden stringers lies flush with the upper surface of the runners to form a grid lying in an even plane for supporting the upper panel of corrugated paperboard.
The composite pallet as described above has a number of advantages, chief among these are low cost and light weight. Of course, low cost is an essential requirement if the pallet is to be disposable after a single use. Furthermore, light weight is highly desirable since pallets create parasitic weight. Often, the weight of the pallet adds to the cost of shipment of the goods supported by the pallets.
The advantages of the present invention are in part due to the grid formed by the notched runners and the wood stringers. The grid efficiently supports the upper panel to support and facilitate the shipment of heavy goods. Moreover, the wood used as transverse stringers has superior bending strength for a given thickness as compared to the corrugated stringers. Therefore, sufficient clearance can be provided beneath the wood stringers to provide for the entry of the forks of a forklift. The attachment of the wood stringers and corrugated runners maintains the spacing and relationship of the runners and prevents the tops of the runners from skewing under load; i.e., tilting relative to a perpendicular relationship with the top and bottom panels. Similarly, the bottom panel ties the lower surfaces of the corrugated runners together to prevent such skewing.
The various components of the composite pallet of this invention functionally interrelate to provide a low-cost, light-weight pallet. Although the pallet construction is sufficiently low in cost so as to be disposable after the first use, at the same time, it is sufficiently durable to allow reuse if desired. Other advantages and features of the composite pallet according to the present invention will be apparent in view of the Detailed Description of the Preferred Embodiment.